Relatives of alleged informers killed by the IRA are preparing for the publication of an interim report into the activities of notorious British army agent Stakeknife.
In 2003 Belfast republican Freddie Scappaticci was named as Stakeknife. He denied the claim.
Scappaticci, who is reported to have died earlier this year, was a former commander of the IRA's Internal Security Unit (ISU), also known as the Nutting Squad, which was responsible for hunting down suspected informers and agents.
Some of those interrogated by the unit were tortured in a bid to extract confessions.
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It is believed Scappaticci, who worked for the British army's Force Research Unit (FRU), joined the IRA's spy-hunting squad as its second-in-command after it was formed in 1978, taking over full control in 1984.
In a recently published book, Stakeknife's Dirty War', by former republican prisoner Richard O'Rawe, it is suggested that Scappaticci's ISU vetted every IRA operation in Belfast between 1986 - 1989 .
Mr O'Rawe also explores the role of a shadowy intelligence oversight body, known as Tasking and Co-ordinating Groups (TCGs), which managed covert operations on behalf of British intelligence agencies.
Led by RUC Special Branch, TCGs included MI5 and elements of the British army - including FRU.
Mr O'Rawe believes that Scappaticci may have had direct knowledge of as many as 35 murders but was responsible for killing only a small number of people himself.
Uncertainty continues over whether all those condemned to death after interrogation by the ISU were in fact working as double agents inside the republican movement.
The potential role and motivation of a high-ranking British agent in the interrogation, potential torture and execution of other suspected agents will no doubt have been central to the team of detectives based in England who have been investigating the activities of Stakeknife since 2016.
Operation Kenova is headed by former Bedfordshire Police Chief Constable Jon Boutcher and is due to report its interim findings in the coming weeks.
The investigation has examined various issues linked to Stakeknife including the role played by security agencies such as MI5.
Last month Mr Boutcher said the interim findings into the activities of Stakeknife had moved a “step closer” to publication after they passed "national security" checks with no changes or redactions.
The delayed report has also been sent to the Public Prosecution Service (PPS) to assess whether it is prejudicial to any future prosecutions.
A spokeswoman for the PPS said a copy of the interim report was received last month.
"We are in the process of ongoing engagement with Operation Kenova which should be concluded shortly," she added.
It is thought the long awaited document could be made public within weeks.
It is understood that some families linked to the Stakeknife investigation will also receive individual reports.
To date, Mr Boutcher's team has given little away both in terms of what has been discovered and how much of Stakeknife's activities will be made public.
For some, several key questions demand answers, including whether or not the lives of their loved ones could have been saved by the state.
Others will want to know, despite how painful the answer may be in some cases, if their loved ones were providing information to the British as alleged.
Whether the Operation Kenova team will provide answers to these questions, either publicly or in private, remains to be seen.
Agencies of the British state have a long standing policy of 'neither confirm nor deny' (NCND) when it comes to sensitive security issues.
Solicitor Kevin Winters, of KRW Law, who acts for some families whose relatives were killed by the ISU, said the report could publicly expose the security forces.
"A number of weeks ago Jon Boutcher indicated his draft report had gone through an intensive security vetting process with all engaged agencies," he said.
"There will be an understandable suspicion on how MI5 and others are able to mark their own home work."
Despite some reservations, he believes that the Operation Kenova interim report could be groundbreaking.
"I think there is a feeling that for the first time ever we will see a report calling out the over-seeing collusive hand of the state in the conflict," he said.
"The key issue for families of victims is the extent of any prior intelligence that some one was going to be killed by PIRA ISU.
"If the report delivers on this then for the first time ever MI5 will be publicly exposed in a way that’s never really happened before."
Mr Winters understands that some of the issues facing the Operation Kenova team present difficulties.
"The issue of NCND (neither confirm nor deny) has traditionally been a very difficult one to navigate and that’s certainly the case here with the Stakeknife investigation," he said.
"How the report will deal with the central allegation that Freddie Scappiticci is 'Stakeknife' will be very challenging."
Operation Kenova was contacted.